I am running Windows 7 64bit, with Visual Studio 2008. I installed the CUDA drivers and SDK. The SDK comes with quite a few examples including compiled executables and sour
Check if you have x64 compiler installed. Then change project type to x64. I had the same problem when trying to compile 32bit cuda program with 64bit win7.
Also make sure you have added 64bit libs and includes to the search path.